大卫·休谟(David Hume)的成名使理性失去了它的崇高地位。自古以来，哲学家们都认为理性是寻找真理的特殊方法。他写道，理性应该是激情的奴隶。休谟的哲学是否破坏了科学和伦理的理性基础?约翰认为休谟的哲学没有这些极端的后果。肯介绍纽约大学教授唐·加勒特。加勒特说，休谟把理性视为心理学家可以研究的东西，他是第一个对认知心理学感兴趣的哲学家。

肯认为休谟的伦理观点破坏了道德。加勒特解释说，休谟说过，除了理性，我们还需要情绪来行动。加勒特将休谟的道德观与康德的道德观进行了对比，认为休谟强调人性。休谟对我们应该做什么有什么看法?加勒特说，休谟认为你应该从发现自己想成为什么样的人开始。休谟认为教育在修炼道德观中起着重要作用。

Why do we think that the future will be like the past? Hume famously argued that inductive arguments are not valid. Hume was a compatibilist, that is, he thought that determinism and free will are compatible. What are Hume's views on religion? He thought religion, on a whole, was a bad thing. How did Hume think we learn things? He thought that everything in our mind was either an impression of the senses or an idea. Reasoning about ideas and impressions produces knowledge. Finally, Ken concludes that Hume put an end to the rationalism of ancient Greek thought.

• Roving Philosophical Reporter(Seek to 04:32): Amy Standen interviews people on the street on what they know about David Hume. She then interviews a retired professor at Stanford University.

• Conundrum(Seek to 47:08): Debra from Oregon asks: do the ends ever justify the means? Suppose someone makes a billion dollars through evil methods but uses the money to a good end. Is this wrong? How do we decide what the right end is?